3-dimensional image display apparatus and control method of the same

ABSTRACT

Provided are a 3-dimensional image display apparatus and a control method thereof, the apparatus including: a video signal receiving unit which receives a video signal containing plane image data or stereoscopic image data from an external signal source; a liquid crystal module which includes a liquid crystal display panel to selectively display the plane image data and the stereoscopic image data, and a backlight unit provided in a rear portion of the liquid crystal display panel; a power supply which supplies power to the liquid crystal module; and a controller which determines whether the received video signal contains the plane image data or the stereoscopic image data, and if the video signal receiving unit contains the stereoscopic image data, the controller controls the power supply such that the backlight unit operates in a power saving mode while the stereoscopic image data is scanned to the liquid crystal display panel.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from Korean Patent Application No.10-2008-0123503, filed on Dec. 5, 2008 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference.

BACKGROUND OF INVENTION

1. Field of Invention

Apparatuses and methods consistent with the present invention relate toa 3-dimensional image display apparatus and a control method of thesame, and more particularly to a 3-dimensional image display apparatusand a control method of the same, which can display an image accordingto dimensions of a video signal input from an external device such as acomputer.

2. Description of the Related Art

With the development of technology, a display apparatus can now processand display various types of a video signal regardless of whether it isdigital or analog. Further, watching a stereoscopic image based on a3-dimensional video signal (hereinafter, referred to as a “stereoscopicvideo signal”) through a monitor, a television or other displayapparatus, has recently become possible.

In general, the stereoscopic video signal has contents dividedcorresponding to left and right eyes of a user as opposed to atwo-dimensional video signal (hereinafter, referred to as a “plane”video signal). Also, the contents are displayed as divided imagescorresponding to the left and right eyes of a user, respectively.

At this time, to enable a user to experience the stereoscopic imagebased on the images being divided to the left and right eyes, apolarized-glass method and a shutter-glass method are employed. Thepolarized-glass method uses a phase-difference filter and theshutter-glass method displays left and right images alternately byswitching a shutter on and off.

However, these related art methods do not provide an image of optimalquality and unnecessarily consume power in processing a stereoscopicvideo signal.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention overcome the abovedisadvantages and other disadvantages not described above. Also, thepresent invention is not required to overcome the disadvantagesdescribed above, and an exemplary embodiment of the present inventionmay not overcome any of the problems described above.

An aspect of the present invention provides a 3-dimensional imagedisplay apparatus including: a video signal receiving unit whichreceives a video signal containing one of plane image data andstereoscopic image data from an external signal source; a liquid crystalmodule which includes a liquid crystal display panel to selectivelydisplay the plane image data and the stereoscopic image data, and abacklight unit provided in a rear portion of the liquid crystal displaypanel; a power supply which supplies power to the liquid crystal module;and a controller which determines whether the video signal receivedthrough the video signal receiving unit contains the plane image data orthe stereoscopic image data, and if the video signal receiving unitcontains the stereoscopic image data, the controller controls the powersupply such that the backlight unit operates in a power saving modewhile the stereoscopic image data is scanned to the liquid crystaldisplay panel.

The liquid crystal module may include: an accommodating container whichis placed in the rear portion of the liquid crystal display panel andaccommodates the backlight unit; and an inverter which is placed in arear portion of the accommodating container and converts the powerreceived through the power supply into driving power to be supplied tothe backlight unit, wherein the controller controls the power suppliedfrom the power supply to the inverter while the stereoscopic image datais scanned to the liquid crystal display panel, so that the backlightunit operates in the power saving mode.

The controller may determine whether the video signal contains thestereoscopic image data on the basis of a vertical blanking interval(VBI) included in the video signal.

If the VBI included in the input video signal is greater than or equalto one of a VBI of a predetermined interval, the controller maydetermine that video signal includes the stereoscopic image data andcontrols the backlight unit to be in the power saving mode.

The predetermined interval may be one of a previous video signal and apreset interval.

The 3-dimensional image display apparatus may further include a userinput unit which is selectable to operate in one of a stereoscopic imagemode and a plane image mode, wherein, if the stereoscopic image mode isselected through the user input unit, the controller determines that thevideo signal received through the video signal receiving unit containsthe stereoscopic image data.

The user input unit may include a hot key.

The 3-dimensional image display apparatus may further include: a memorywhich stores at least one on screen display (OSD) data; and an OSDgenerating unit which generates an OSD scene to provide an option forselecting the one of the stereoscopic image mode and the plane imagemode.

The backlight unit may include at least one cold cathode fluorescentlamp, and the controller may control the power supply to turn off the atleast one cold cathode fluorescent lamp in the power saving mode whilethe stereoscopic image data is scanned to the liquid crystal displaypanel.

The backlight unit may include a plurality of light emitting diodes(LED), and the controller may control the power supply to decrease powersupplied to the plurality of LEDs in the power saving mode while thestereoscopic image data is scanned to the liquid crystal display panel.

Another aspect of the present invention is achieved by providing acontrol method of a 3-dimensional image display apparatus including abacklight unit and a liquid crystal display panel, the control methodincluding: receiving from an external source a video signal containingone of plane image data and stereoscopic image data; determining whetherthe received video signal contains the plane image data or thestereoscopic image data; and controlling the backlight unit to operatein a power saving mode while the stereoscopic image data is scanned tothe liquid crystal display panel if the received video signal containsthe stereoscopic image data.

The determining whether the received video signal contains the planeimage data or the stereoscopic image data may include comparing avertical blanking interval (VBI) of the video signal and a predeterminedvalue.

The determining whether the received video signal contains the planeimage data or the stereoscopic image data may further includedetermining if the VBI is greater than or equal to the predeterminedvalue.

The predetermined value may be one of a VBI of a previous video signaland a preset interval.

The controlling of the backlight unit may further include controllingthe backlight unit to operate in a normal mode during the VBI of thevideo signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects of the present invention will becomeapparent and more readily appreciated from the following description ofthe exemplary embodiments, taken in conjunction with the accompanyingdrawings, in which:

FIG. 1A is a block diagram of a 3-dimensional image display apparatusaccording to an exemplary embodiment of the present invention;

FIG. 1B is a sectional view of a liquid crystal module of the displayapparatus of FIG. 1A;

FIG. 2 is a timing diagram for explaining an operation of a3-dimensional image display apparatus according to an exemplaryembodiment of the present invention;

FIGS. 3A and 3B are flowcharts for explaining a control method of the3-dimensional image display apparatus according to an exemplaryembodiment of the present invention;

FIG. 4 is a block diagram showing a 3-dimensional image displayapparatus according to another exemplary embodiment of the presentinvention;

FIG. 5 is a view showing an exemplary embodiment of an on screen display(OSD) scene of the 3-dimensional image display apparatus of FIG. 4; and

FIG. 6 is a flowchart of for explaining a control method of the3-dimensional image display apparatus according of FIG. 4.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

Below, exemplary embodiments of the present invention will be describedin detail with reference to accompanying drawings so as to be easilyrealized by a person having ordinary knowledge in the art. The presentinvention may be embodied in various forms without being limited to theexemplary embodiments set forth herein. Descriptions of well-known partsare omitted for clarity, and like reference numerals refer to likeelements throughout.

Referring to the accompanying drawings, exemplary embodiments of thepresent invention are as follows.

FIG. 1 illustrates a 3-dimensional image display apparatus according toan exemplary embodiment of the present invention.

As shown in FIG. 1A, the 3-dimensional image display apparatus 10according to an exemplary embodiment of the present invention includes avideo signal receiving unit 11 to receive a video signal having planeimage data or stereoscopic image data from an external signal source 1such as a computer; and a liquid crystal module 12 including a liquidcrystal display panel 12-1 to selectively display the plane image dataand the stereoscopic image data, and a backlight unit 12-2 provided inthe rear of the liquid crystal display panel 12-1.

Further, the 3-dimensional image display apparatus 10 includes a powersupply 13 which supplies power to the liquid crystal module 12, and acontroller 14 which controls the power supply 13 such that the backlightunit 12-2 operates in a power saving mode while scanning thestereoscopic image data to the liquid crystal display panel 12-1 if itis determined that the video signal received through the video signalreceiving unit 11 contains the stereoscopic image data.

Here, the external signal source 1 may be achieved by not only thecomputer but also diverse multimedia reproducers which can convertvarious multimedia digital files into displayable signals.

The video signal receiving unit 11 may be achieved by an interfaceconnectable to the external signal source 1. For example, the videosignal receiving unit is achieved by a digital video interface (DVI)connector to receive a digital signal, a D-Sub connector to receive ananalog signal, a universal serial bus (USB) port or the like variousserial-type interface ports, or a wire/wireless network port.

Meanwhile, a buffer memory 14-1 is connected to the controller 14 andtemporarily stores data therein so that the video signal received in thecontroller 14 can be converted to have a format to be displayablethrough the liquid crystal display panel 12-1.

As shown in FIG. 1B, the liquid crystal module 12 may include anaccommodating container 12-4 placed in the rear of the liquid crystaldisplay panel 12-1 and accommodating a plurality of cold cathode lamps12-3 as the backlight unit 12-2, and an inverter 12-5 placed in the rearof the accommodating container 12-4 and converting the power receivedthrough the power supply 13 into driving power to be supplied to thebacklight unit 12-2. Further, the liquid crystal module 12 includes alight guide plate 12-6 and a plurality of various optical sheets 12-7,which are placed between the backlight unit 12-2 and the light crystaldisplay panel 12-1. Light emitted from the backlight unit 12-2 isuniformly irradiated to the liquid crystal display panel 12-1.

In FIG. 1B, the backlight unit 12-2 is provided as a direct type inwhich a light source emits light in the rear of the light guide plate,but not limited thereto. Alternatively, the backlight unit 12-2 may beprovided as an edge type in which a light source is placed at lateralsides of the light guide plate.

Further, the backlight unit 12-2 may include at least one cold cathodefluorescent lamps (CCFL), at least one external electrode fluorescentlamp (EEFL), a plurality of light emitting diodes (LED), or the likevarious light sources.

The power supply 13 generally receives alternating current (AC) powerfrom the outside, and supplies the AC power to various devices such asthe backlight unit 12-2 of the liquid crystal module as it is convertedinto direct current (DC) or AC voltage, thereby driving the displayapparatus.

Below, a control method of a 3-dimensional image display apparatusaccording to an exemplary embodiment of the present invention will bedescribed with reference to FIGS. 2 and 3.

According to this exemplary embodiment of the present invention, the3-dimensional image display apparatus 10 can selectively display theplane image data for the 2-dimensional image or the stereoscopic imagedata for the 3-dimensional image output from the external signal source1.

Further, the plane image data or the stereoscopic image data isdisplayed as one frame on the liquid crystal display panel by a verticalsynchronous signal contained in the video signal. Here, one verticalsynchronous interval, i.e., an interval corresponding to one frame, isdivided into an activated interval during which data is scanned, and avertical blanking interval (VBI) during which data scanning iscompleted.

That is, the VBI divides the frames from each other. In other words, theVBI is a time taken in returning an electron beam from an electron gunprovided inside a cathode ray tube (CRT) to an initial position.Therefore, there is no need of the VBI if a display device is a liquidcrystal display panel. Nevertheless, the video signal is provided withthe VBI in consideration of keeping compatibility between the displaydevices. In the case of the CRT display device, no image data isdisplayed on a screen during the VBI. On the other hand, in the case ofthe liquid crystal display panel, each pixel is driven by the liquidcrystal display panel to keep its color and intensity, and thus thescanned image is displayed during the VBI.

Meanwhile, (a) in FIG. 2 shows a vertical synchronous interval of thevideo signal containing the plane image data. At this time, the VBIoccupies less than 25% of a total vertical synchronous interval, butthis percentage may be varied depending on resolutions supportable bythe liquid crystal display panel 12-1.

On the other hand, when the stereoscopic image data is displayed on theliquid crystal display panel 12-1, as shown in (b) of FIG. 2, the VBI islarger than that of the video signal containing the plane image data andoccupies 25% or more of the vertical synchronous interval total.Likewise, this percentage may also be varied depending on theresolutions supportable by the liquid crystal display panel 12-1.

In the case that a user uses shutter-type glasses to watch astereoscopic image through the 3-dimensional display apparatus accordingto an exemplary embodiment of the present invention, the VBI correspondsto a period of time when a left eye shutter or a right eye shutter isbeing opened.

To watch the stereoscopic image data displayed on the liquid crystaldisplay panel 12-1, a user wears shutter-type stereoscopic glasses. Inthis case, the liquid crystal display panel 12-1 displays the image datafor the left eye and the image data for the right eye alternately.Corresponding to the image data for the left eye and the image data forthe right eye, a left shutter and a right shutter of the stereoscopicglasses are alternately opened to thereby allow a user to watch an imagedisplayed on the liquid crystal display panel 12-1.

At this time, an interval during which the image data for the left eyeis displayed as a full screen of the liquid crystal display panel 12-1is the VBI after the image data for the left eye is completely scannedon the panel, and likewise an interval during which the image data forthe right eye displayed as a full screen of the liquid crystal displaypanel 12-1 is also the VBI after the image data for the right eye iscompletely scanned on the panel.

Accordingly, in the case of the shutter-type stereoscopic glasses, ashutter for the right eye is opened during the VBI following anactivated interval during which the image data for the right eye isscanned, and a shutter for the left eye is opened during the VBIfollowing an activated interval during which the image data for the lefteye is scanned. Thus, the open time for each shutter gets longer as theVBI becomes longer, so that a time during which the image is displayedincreases, thereby enhancing recognition of the image based on the imagedata.

Further, the left shutter and the right shutter are kept closed duringthe activated interval in which the image data for the right or left eyeis scanned, so that a user cannot watch the screen.

Meanwhile, (c) of FIG. 2 shows that the backlight unit 12-1 of the3-dimensional image display apparatus operates in the power saving mode.As shown therein, the backlight unit 12-2 operates in the power savingmode during the activated interval in which the image data is scanned,but operates in a normal mode during the VBI.

Referring to FIG. 3A, a control method of the 3-dimensional imagedisplay apparatus is as follows. First, at operation S10, a video signalcontaining stereoscopic image data is received. Next, at operation S20,the controller determines whether the received video signal containsstereoscopic image data. If the controller determines the received videosignal contains stereoscopic image data (S20-Y) then, at operation S30,the controller 14 drives the backlight unit 12-2 in the power savingmode while the stereoscopic image data is scanned, i.e., during theactivated interval, but drives the backlight unit 12-2 in the normalmode while the shutters for the left and right eyes are opened, i.e.,during the VBI. On the other hand, if the controller determines thereceived video signal contains stereoscopic image data (S20-N), theprocess ends.

FIG. 3B is a flowchart for explaining detail control of power to besupplied to the backlight unit 12-2. If the video signal is received atthe operation S10, the controller 14 counts horizontal and verticalsynchronous signals contained in the video signal at operation S21.

At operation S22, the controller 14 determines resolution of a videosignal, and determines whether or not its VBI included in the verticalsynchronous interval is larger than a predetermined value. Thepredetermined value can be, for example, the VBI of a previous videosignal or a preset interval. As a result, if the VBI of the input videosignal is larger than or the same size as the VBI of the previous videosignal or the preset interval, the controller 14 determines that thecurrently input video signal contains the stereoscopic image data atoperation S23, and controls the power supplied to the backlight unit12-2 of the liquid crystal module 12 to be in the power saving modeduring the activated interval in which the stereoscopic image data isscanned at operation S24. Here, the power saving mode can be achieved bydecreasing or intercepting (i.e., powering off) the power supplied tothe cold cathode fluorescent lamp (CCFL) or the light emitting diode(LED) included in the backlight unit 12-2.

Some of the plural lamps or LEDs may be turned off, or all of them maybe turned off. The controller 14 adjusts the power supplied from thepower supply 13 to the inverter 12-5 in order to control the drivingpower supplied to the backlight unit 12-2. It will be appreciated thatthe normal mode for normally supplying the power to the backlight unit12-2 is carried out during the VBI in which the data for the left orright eye is displayed as the full screen of the liquid crystal displaypanel 12-1.

Here, the preset interval, to be compared with the VBI of the inputvideo signal so as to determine whether the input video signal includesplane image data or stereoscopic image data, may be optionally set in auser mode or a manufacturer mode according to resolution correspondingto the number of pixels of the liquid crystal display panel or drivingtiming of the liquid crystal display panel.

Also, the preset interval may be set as the VBI of the previous videosignal displayed on the liquid crystal display panel, so that it isdetermined that the currently input vide signal contains thestereoscopic image data if the VBI of the currently input video signalis larger than that of the previous video signal, thereby controllingthe backlight unit 12-2 to operate in the normal mode with normal powersupply during only the VBI and in the power saving mode during theinterval in which the image data is scanned.

On the other hand, if the VBI of the currently input video signal issmaller than the VBI of the previous video signal or the presetinterval, it is determined at operation S25 that the currently inputvideo signal contains the plane image data, and thus the backlight unit12-2 operates in the normal mode at operation S26.

FIG. 4 is a block diagram showing a 3-dimensional image displayapparatus according to another exemplary embodiment of the presentinvention.

As shown therein, the 3-dimensional image display apparatus according tothis exemplary embodiment includes a user input unit 15 for a user'sselection, an on screen display (OSD) generating unit 16 which generatesan OSD scene as a user interface, and a memory 17 which stores OSD datatherein.

The user input unit 15 may be provided as a button such as a hot keyincluded in the 3-dimensional image display apparatus, a remotecontroller or the like. Alternatively, the user input unit 15 may beprovided as a typical input unit such as a touch panel, a mouse, etc.Thus, a user can optionally setup a stereoscopic image mode or a planeimage mode through the user input unit 15.

The memory 17 stores various data about a font size, a color, an image,etc. included in the OSD scene I.

The OSD generating unit 16 generates the OSD scene I under control ofthe controller 14 to thereby allow a user to select either of thestereoscopic image mode or the plane image mode, and displays the OSDscene I on the liquid crystal display panel 12-1. FIG. 5 is a viewshowing an exemplary embodiment of the OSD scene I of the 3-dimensionalimage display apparatus. The OSD scene I includes items about the“stereoscopic image mode” or the “plane image mode,” and overlaps withthe video signal being displayed on the liquid crystal display panel12-1. At this time, transparency of the OSD scene I may be controlledfreely. Also, each item of the OSD scene I is highlighted when selectedby a user.

FIG. 6 is a flowchart of for explaining a control method of the3-dimensional image display apparatus according of FIG. 4. Referring toFIG. 6, the control method of the controller 14 is as follows.

First, a video signal is received from the outside at operation S100,and then the controller 14 determines whether a display mode is setup asthe stereoscopic image mode through the user input unit 15 at operationS200.

In result, if it is determined that the stereoscopic image mode isselected by a user, at operation S300 the backlight unit 12-2 operatesin the power saving mode while the stereoscopic image data is scanned.That is, according to this exemplary embodiment, in the case that thestereoscopic image data is input, a user may select control for drivingthe backlight unit 12-2 to operate in the power saving mode during acertain interval. When the stereoscopic image mode is selected by auser, the controller 14 drives the backlight unit 12-2 to operate in thepower saving mode while the stereoscopic image data is scanned.

On the other hand, in the case that a user selects not the stereoscopicimage mode but the plane image mode, the controller 14 drives thebacklight unit 12-2 to operate in the normal mode regardless of whetherthe video signal contains the stereoscopic image data or not, atoperation S400.

In the display apparatus receiving stereoscopic image data according toan exemplary embodiment of the present invention, the power saving modeis achieved by a user's selection or automatically during a certaininterval.

Although a few exemplary embodiments of the present invention have beenshown and described, it will be appreciated by those skilled in the artthat changes may be made in these exemplary embodiments withoutdeparting from the principles and spirit of the invention, the scope ofwhich is defined in the appended claims and their equivalents.

1. A 3-dimensional image display apparatus comprising: a video signalreceiving unit operable to receive a video signal containing one ofplane image data and stereoscopic image data from an external signalsource; a liquid crystal module which includes a liquid crystal displaypanel to selectively display the plane image data and the stereoscopicimage data, and a backlight unit provided in a rear portion of theliquid crystal display panel; a power supply which supplies power to theliquid crystal module; and a controller which determines whether thevideo signal received through the video signal receiving unit containsthe plane image data or the stereoscopic image data, and if the videosignal receiving unit contains the stereoscopic image data, thecontroller controls the power supply such that the backlight unitoperates in a power saving mode while the stereoscopic image data isscanned to the liquid crystal display panel.
 2. The 3-dimensional imagedisplay apparatus according to claim 1, wherein the liquid crystalmodule comprises: an accommodating container which is placed in the rearportion of the liquid crystal display panel and accommodates thebacklight unit; and an inverter which is placed in a rear portion of theaccommodating container and converts the power received through thepower supply into driving power to be supplied to the backlight unit,wherein the controller controls the power supplied from the power supplyto the inverter while the stereoscopic image data is scanned to theliquid crystal display panel, so that the backlight unit operates in thepower saving mode.
 3. The 3-dimensional image display apparatusaccording to claim 2, wherein the controller determines whether thevideo signal contains the stereoscopic image data on the basis of avertical blanking interval (VBI) included in the video signal.
 4. The3-dimensional image display apparatus according to claim 3, wherein ifthe VBI included in the input video signal is greater than or equal to apredetermined value, the controller determines that video signalcontains the stereoscopic image data and controls the backlight unit tobe in the power saving mode.
 5. The 3-dimensional image displayapparatus according to claim 4, wherein the predetermined value is oneof a VBI of a previous video signal and a preset interval
 6. The3-dimensional image display apparatus according to claim 2, furthercomprising a user input unit which is selectable to operate in one of astereoscopic image mode and a plane image mode, wherein, if thestereoscopic image mode is selected through the user input unit, thecontroller determines that the video signal received through the videosignal receiving unit contains the stereoscopic image data.
 7. The3-dimensional image display apparatus according to claim 6, wherein theuser input unit comprises a hot key.
 8. The 3-dimensional image displayapparatus according to claim 6, further comprising: a memory whichstores at least one on screen display (OSD) data; and an OSD generatingunit which generates an OSD scene to provide an option for selecting theone of the stereoscopic image mode and the plane image mode.
 9. The3-dimensional image display apparatus according to claim 2, wherein thebacklight unit comprises at least one cold cathode fluorescent lamp, andthe controller controls the power supply to turn off the at least onecold cathode fluorescent lamp in the power saving mode while thestereoscopic image data is scanned to the liquid crystal display panel.10. The 3-dimensional image display apparatus according to claim 2,wherein the backlight unit comprises a plurality of light emittingdiodes (LED), and the controller controls the power supply to decreasepower supplied to the plurality of LEDs in the power saving mode whilethe stereoscopic image data is scanned to the liquid crystal displaypanel.
 11. A control method of a 3-dimensional image display apparatusincluding a backlight unit and a liquid crystal display panel, thecontrol method comprising: receiving from an external signal source avideo signal containing one of plane image data and stereoscopic imagedata; determining whether the received video signal contains the planeimage data or the stereoscopic image data; and controlling the backlightunit to operate in a power saving mode while the stereoscopic image datais scanned to the liquid crystal display panel if the received videosignal contains the stereoscopic image data.
 12. The control methodaccording to claim 11, wherein in the power saving mode, the powersupplied to the backlight unit is controlled.
 13. The control methodaccording to claim 11, wherein in the power saving mode, the powersupplied to the backlight unit is turned off.
 14. The control methodaccording to claim 11, wherein the determining whether the receivedvideo signal contains the plane image data or the stereoscopic imagedata includes comparing a vertical blanking interval (VBI) of the videosignal and a predetermined value.
 15. The control method according toclaim 14, wherein the determining whether the received video signalcontains the plane image data or the stereoscopic image data furtherincludes determining if the VBI is greater than or equal to thepredetermined value.
 16. The control method according to claim 15,wherein the predetermined value is one of a VBI of a previous videosignal and a preset interval.
 17. The control method according to claim11, wherein the controlling the backlight unit further includescontrolling the backlight unit to operate in a normal mode during theVBI of the video signal.